There are two machines that produce aluminum cans. the newer machine can produce 7200 cans in 200 minutes. it takes the older machine 300 minutes to produce that many cans . if the two machines work together, how long will it take them to produce 7200 cans

The first machine can generate 36 cans a minute. The old machine can generate 24 cans a minute. Both machines working together generate 60 cans a minute. 7200 cans divided by 60 means it will take 120 minutes. You can check this: 36*120+24*120=7200